To assess the accuracy of species delimitation in the genus Aphaenomurus Yosii, we conducted a comparative micro-morphological study and molecular analysis using two mitochondrial (COI, 16S) and two nuclear genes (18S, 28S) on 118 specimens from 24 localities. The results showed that the morphological characters of A. vicinus and A. interpositus, as presented in the original description, were intermixed in phylogenetic lineages within the genus and did not form independent lineages. Furthermore, there were enough differences among Aphaenomurus individuals to be considered as morphologically distinct species (Th. III is 1+1 or 2+2, Abd. I is 2+2 or 3+3, Abd. II is 2+2 or 3+3), but they do not form an independent lineage. Molecular and morphological analyses have determined that A. vicinus and A. interpositus are the same species, exhibiting morphological variation in dental spines formula, claws, chaetotaxy, and other features. Additionally, the genus Aphaenomurus forms a monophyletic clade, which is further divided into several lineages within the genus. No morphological differences were observed to distinguish these lineages. This cladistic divergence is attributed to heteroplasmy, which is supported by previous studies that have suggested the possibility and problems of heteroplasmy in Collembola, and by the high genetic distances between individuals in the mitochondrial genes of Aphaenomurus.

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis (proportion spawned: 45.5%), Corbicula fluminea (12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings’ eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/ larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/ larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling’s spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling’s embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.

The occurrence of Laodelphax striatellus (SBPH) in Korea ranged 0.3-19.3 individuals in 2021, and 0.3-23.3 individuals in 2022 during the investigation period. Nilaparvata lugens (BPH) was not observed in 2021, but N. lugens (BPH) showed the highest number(82.0 inds.) in late September of 2022. The occurrence of Sogatella furcifera (WBPH) was not severe during the study period. Compared to Korea’s situation, N. lugens (BPH) and S. furcifera (WBPH) in Asian regions showed high occurrence in Bangladesh and Sri Lanka. The results of the field survey could be confirmed with the occurrence pattern of about once or twice in their regions. Continuous monitoring is required for the best control of planthopper species in rice production regions of Asia. We anticipate that exchange of occurrence information and establishment of a control cooperation system will improve rice productivity in Asian regions by preventing outbreak of planthopper species and reducing damages caused by the species.

Orussidae is a unique family belonging to the ‘Symphyta’, Hymenoptera. It is a small group of parasitoid sawflies, consisting of about 90 known extant species in 15 genera in the world. Most species of Orussidae are thermophilous and imagines are active during the hottest hours of the day. Therefore, orussids are rarely collected. They are known to be idiobiont ectoparasitoids of larvae of wood-boring beetles such as Buprestidae and Cerambycidae or Hymenoptera such as Siricidae and Xiphydriidae, although records of orussids parasitizing introduced siricids in New Zealand do not constitute a natural host relationship. Within the family, Orussus is the largest and most widely distributed genus. Currently, 28 valid species are recognized. Recently, Vilhelmsen et al. (2014) reported three new species of the genus Orussus from the Oriental region. Here we describe a new species, Orussus sp. nov., from South Korea and provide a revised key to the eastern Palaearctic species of Orussidae. Also, phylogenetic analyses place the new species basally in Orussus, together with other species from the Far East.

The genus Psallus Fieber, 1858 (Phylini) is the largest group, with twenty six described species in Korea (Duwal et al., 2012). Due to recent collection in 2013, three new species are recognized from Korea. All these species are described, with images of dorsal habitus and genital structures. A checklist of the East Asian species and geographic distribution of Psallus is revised.

Nine previously described forms of Asian Pheidole species are synomimized, based on the reexamination of the type materials: Pheidole attila Forel, 1913 is synonymized with P. capellinii Emergy, 1887; Pheidole exasperata var. concordia Santschi, 1916 and P. e. var. fusiformis Viehmeryer, 1914, with P. aglae Forel, 1913; P. multicoma Eguchi, 19999, with P. comata F. Smith, 1858; P. havilandi var. sapuana Foreal, 1911 and P. h. var. selangorensis Forel, 1913, with P. havilandi Forel, 1911; P. huberi var. perakensis Forel, 1911, with P. huberi Forel, 1911; P. nodgii r. maxwellensis Forel, 1913, with P. magrettii Emery, 1887; P. treubi Forel, 1905, with P. noda Fr. Smith, 1874. P. nodgii var. tjibodana Forel, 1905 and P. sauberi subsp. sarawakana Forel, 1911 are considered to the good biological species. Lectotypes are designated for 31 forms of Asian Pheidole. Either rediscription or taxonomic remarks are given for each species.